Generally, in a method and apparatus for cleaning dust-containing gases, there is conventionally adopted a system wherein a dust-containing gas current is brought into contact with such washing liquid as water and the dust in the gas is caught with the washing liquid. The principle of bringing a dust-containing gas into contact with a washing liquid to make the washing liquid catch the dust in said gas is confirmed and this conventional system is extensively worked.
However, in this conventional system, the rate of contact of the dust in the gas with the washing liquid is not always sufficiently high, and the actual dust removing effect has not been so high.
The present invention improves the rate of contact of the dust in the gas and the washing liquid with each other.
It has been discovered that the dust in the gas current in the conventional system will be most readily caught in the washing liquid only in the moment the washing liquid is fed into said gas current but, with the lapse of time, the washing liquid will ride the gas current and will begin to move and, when the washing liquid comes to move at a velocity equal to that of the gas current, the rate of contact of the dust with the washing liquid will be a minimum.
It is presumed to be so because, when the moving velocity of the washing liquid and the moving velocity of the dust become equal or approximately equal to each other, the possibility of the dust coming into contact with the washing liquid in the advancing direction of the dust will become nil and, even if the dust overtakes the washing liquid or the washing liquid overtakes the dust, they will pass each other without coming into contact due to swirls formed around each of them.
Among the conventional apparatus, there is a venturi scrubber type dust removing apparatus wherein, in order to bring the dust and washing liquid into contact with each other, the dust-containing gas current is throttled with a venturi tube to increase the velocity of said gas current.
However, such conventional apparatus has difficulty in that the pressure loss is so large that, in the case of treating a large volume, a large power source will be required.